Leather forming machine



2 SheetsSheet 1 J. T. RIDDELL LEATHER FORMING MACHINE Filed Dec. 18, 1955 m 5 n w 1| Z I. V w 1 I I 2 4 W mpg/H H fli'l m W m a M W W! W u Junie 25, 1935.

In men for John 7 ffidaell U/z'i'n asses:

June 25, 1935. J T, RlDDELL LEATHER FORMING MACHINE Filed De c. 18, 1953 2 Sheets-Sheet 2 Z'm/en for John T Rz'aa'el/ Patented June 25, 1935 v I l v UNITED STATES {PATENT {OFFICE 'LEATI-IER FORMING John T. BiddelLChicago, r11. Application December18,'193 3 Serial :No. #02318 l seams; (ores-1) This inventionrelates to the arts of stretcli- In the form shown, the machine comprises a ing and forming leather, and has particular rerframe I having a table-like bed lower the mid :erence-to the formation of spheroidal segments die of which'there is mounted a support or cross of leather intended for assembly to form foothead 3 havin'g ari upstanding centering pin 4, 5 balls, basket balls, volley balls, and the 'like'. and providing a seatfor a formblock 5ove'r 5 The main objects ofthis' invention are'to prowhich thel leather ball sections 6 are, to be vide an improved form of machine for stretchstretchedj; I t ing'leather-on a convex form; toprovide a ma- Arranged ina circle or ring aboutthe support chine of this kind whereby the amount of stretch- 3 isa series "of stretchermembers which are in- 10 ing can be accurately gauged and whereby the dividually swingable in radial planes with respect leather will be subjected in its preliminary to the centerlof the support 3. Each of the stretching to substantially uniform pull in all stretcher members in the form shown consists of directions radiating from a common center; aclamp 1, a spring balance element 8', and a I and to provide apparatus of this kind which-is turnbuckleil, and is hinged to the table 2;. j especially adapted'for rapid operation such as is JI'he support 31is' carried'by a pair of ,vertical- 15 consistent with modern mass production manuly-disposediods lll which are slidably mounted. iacturing operations. in suitable bearings in the bed 2 and are con- A specific embodiment of this invention is ilnected at their lower ends with a crosshead or lustrated in the accompanying drawings in nut II which is internally threaded to fit the which: jack shaft l2 which is journaled at l3 in the bed 20 Figure 1 is a side elevation, with parts of the 2 and in a cross frame M in the lower P t Of frame in section, of a leather stretching machine the frame I. The shaft I2 has an anti-friction constructed according to this invention and esst b a I5 011 top of the cross bar l4 and pecially designed for forming leather ball segis driven by han wh l 6 in hr h bevel d 5 ments of spheroidal shape. For the sake of gears clearness and simplification of the drawing, some In d r to provide for gripp leathers of of the stretcher clamps and their associated vario s h h f the mp 1 has a I assemblies are also omitted, fixed jaw 18 and a pivoted cam-shaped serrated Fig. 2 is a longitudinal sectional detail of one J' W Op d y a level Eaeh Clamp T of t stretcher members is provided with a clevis 2| at its lower end for 30 Fig. 3 is a, plan i of t maehine'ona, email pivotal connection with a threaded stem 22 scale illustrating the radial arrangement of the vWhich in turn is ct d by the urnbuckle stretcher members, with a threaded stem 23 connected with the Fig. 4;is a sectional detail showing the relation I Plunger 24 0f e p n a a c el t The of theform block to its supporting cross head. plunger 24 has a head 25 at its lower e diw 35 Fig. 5 is a detail illustrating a form of ball an indicator 26 extending through a slot in the section such as is formed in the machine illusshell 0f the p balance t. trated. A compression spring 28 bears between the Fig. 6 is a sectional detail illustrating the purhead 25 and the head 29 0f the Shell 40 pose of the groove in the block to accommodate Stems 22 and 2| of course, threaded right 40 the central se m of th b ll ti and left respectively. The spring balance ele- Fig. 7 is a perspective i of t type of bail ment has a clevis connection with a pad 30 boltthat is made by assembling sections such as iled to the bed The P 39 a S d t0 lustrated in Fi ur 5, receive the bolts 301, thus admitting of ad ust- The machine shown in the drawings is parment to adapt the stretcher elements to various 45 ticularly designed for mass production of pre- Stretcher block formed leather segments which are to be assem- The Operation of the devlee Shown is as lbled in the manufacture of footballs, basket balls, IOWSI volley balls and the like, where it is desirable T particular conformation o t m block that the finished ball shall accurately conform .to 5 is, of Course, determined y the yp of a l a predetermined spherical, spheroidal or oval which is bei manufactured. In 1Jhe form shape and which segments should be uniformly shown in the drawings, the block is designed for treated in the process of manufacture so thatthe making spherical balls of the type illustrated in finished balls will remain true to form through- Figure 7 in which the surface is divided into out a long period of usage. six main sections of spherically rectangular form and each of these sections is made up of two pieces. These two pieces are cut to suitable form, sewn together so as to roughly approximate the curvature of the mold. The section is then soaked in water to render the leather pliable and laidover the mold block 5 as in Figure 1, the mold block being grooved to accommodate the seam between the two parts. The clamps I are then fastened to the margins of the leather sheetcat uniformlyspaced intervals around its entire perimeter and by means of the turnbuckles 9 the tension on all of the'str'etcher elements is equalized by bringing the indicators 26 of the spring balance in line with the same respective scale graduation on the'shells. i a i By turning the handwheel IS the jack is operv ated to lift the crosshead 3 and formblock'to a distance determined by watching the scale on one of the spring balances and stopping when the pointer indicates the desired strain to which the leather is to be subjected, this being determined by experience. 7 I t a I 'The margins ofthe leather'sheet 'arethen secured to. the block 5 by a row of'tacks indicated at 3|. and the operation is repeated, with a new block 5 and a new sheet of leather. The formblocks are preferably made of hardwood such as maple. The term leather as herein used is intended to include leather compositions and any other sheet material which might be substituted I therefor and to the stretching and forming of. which the invention is applicable; l

Although but one specific embodimentof this invention is herein shown and described, it is to be understood that numerous details, 'of the The clamps are then thrown on members.

'2-;A device of the class described comprising a central support having a seat for a form block, a series of stretcher members arranged in a ring about said'support leather gripping clamps on theends of said stretcher members, turnbuckles interposed in said stretcher members for longitudinal adjustment thereof, spring balance elements interposed in said stretcher members, and

jack meansacting to shift said support relative to said stretcher member's. v j

' 3. A device of theclass described comprising a support for a sheet of leather, a series of individually adjustable stretcher members a s tioned andarranged to grip themargin of such sheet of leather, means associated with each of said stretcher members arranged to indicate shift said support relative to said stretcher theamount oftension therein, and means coacting with said stretcher members for simultaneously increasing their vpulljon the margins 01 said sheet. a

, JOHNT. Rm ELL, i 

